Bapi's or Idocs ?

[Estelle BOUAT]

Hello all,
 
SAP says in the doc online 4.6C (BC-Midlleware =3D> ALE =3D> ALE programm=
ing Guide =3D> Purpose) : =
 
 
"Distribution Using BAPIs: This process has been supported since R/3 Rele=
ase 4.0A and is the basis for future developments. =
 
Distribution Using Message Types. ALE developments in R/3 Release 3.x are=
 based on this programming model."
 
Does anybody know what does it mean ?
 
If I have to develop interfaces between two systems : =
 
- may I have use Message Type (I guess that means Idocs) ?
- or may I have use Bapi's?
- what is the future of the idocs ?
 
We have an experience with an interface between SAP BBP and an R/3 backen=
d, we used a Bapi (with a g=E9n=E9ration of Idoc) but we have several Bac=
kends R/3 et we can't use to day this solution, we have to use only Idocs=
 and ALE.
so what is the better solution ?
 
Is it depend on something ? and what ?
 
Thank you for yor response.
 
Estelle